[Background Art]
Conventionally, a virtual machine system is known that includes a plurality of processors and executes a plurality of virtual machines in parallel with use of the processors (see Patent Literature 1).
In such a virtual machine system, each virtual machine is allocated to one or more processors and is then executed.
If the number of processors is larger than the number of virtual machines, the virtual machines may not be allocated to some of the processors.
Also, as a technique for reducing power consumption in a virtual machine system including a plurality of processors, techniques disclosed in Patent Literatures 2 and 3 are conventionally known.
According to the technique in Patent Literature 2, if a virtual machine is not allocated to any of the processors in a virtual machine system, a power supply to the processor is cut off. According to the technique in Patent Literature 3, if a virtual machine is not allocated to any of the processors in a virtual machine system, the processor is placed in a sleep state.